Many children with autism or other developmental disorders tend to eat an extremely narrow range of foods, and this may put them at risk for serious health problems, said Dr. Melody Duvall, lead author of the case report, which was published online Nov. 4 in the journal Pediatrics.

What is it about autism that often makes children resistant to eating a normal and varied diet? One expert had some theories.

"We know many children with autism spectrum disorder have sensory issues, are overly sensitive to certain textures, sounds and perhaps tastes," said Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at the Steven & Alexandra Cohen Children's Medical Center in New Hyde Park, N.Y. "And many children with an autism spectrum disorder will have an insistence on sameness, are comfortable with routines and have difficulty with transitions."

Those traits often make children insist on eating only a very limited combination of foods, Adesman explained.

"This case report highlights how atypical and narrow the diets are with some children with autism or other severe developmental problems, and that the potential for serious health consequences can follow," said Adesman.

In the case of the 9-year-old boy, the situation was extremely challenging to figure out, explained Duvall, his physician at Boston Children's Hospital. He came to the emergency department twice, complaining of hip pain so severe he refused to walk. Physicians looked for neurological or orthopedic reasons for the limp, but found no underlying cause. Physical therapy only worsened his discomfort. He had the usual blood tests, and they were normal.

The physicians then thought he might have Lyme disease, but it was ruled out, Duvall said. He then started developing serious lung and heart problems, had a rapid heart rate, dry cough and difficulty breathing. Eventually, he became so ill he was taken to the intensive care unit, she added.